January 24, 2006
The authors of the current study sought to explore risk behavior and transmission routes in men having sex with men (MSM) newly diagnosed with sexually transmitted infections (STIs).
Physicians participating in the sentinel study completed a questionnaire on clinical diagnosis and manifestation site for acute STIs, while patients contributed information on sexual risk behavior and likely STI transmission route.
Of the 356 diagnosis forms and 169 matching patient questionnaires analyzed, syphilis was the most frequent diagnosis (n=147; 33 percent primary syphilis with ulcer localization, 71 percent genital, 22 percent anorectal, and 8 percent oral; 67 percent secondary syphilis), followed by gonorrhea (n=136; 59 percent genital, 34 percent rectal, 7 percent pharyngeal) and Chlamydia trachomatis infection (n=51; 48 percent genital, 48 percent rectal, 4 percent pharyngeal). More than one infection was diagnosed in 12 patients, and two or three sites were affected in 11 patients. About 60 percent of STIs were acquired by genital-oral and oral-anal practices. Unprotected anal intercourse (UAI) was reported more frequently by HIV-positive men (mostly receptive) and MSM with high numbers of partners.
"High partner numbers, an important role of genital-oral sexual practices for the transmission of STIs, and relatively high frequencies of mostly receptive UAI in HIV-positive men are all contributing to increasing STI incidences among MSM," the researchers concluded.